Process of uniting broken pieces of arc-light carbons



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N. P. STEVENS. PROCESS OF UNITING BROKEN PIEGES 0]? ARC LIGHT GARBONS.

No. 488,256. Patented Dec. 20, 1892.

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N. P. STEVENS.

PEOEESS 0E UNITING BROKEN PIECES OF ARC LIGHT 'GARBONS. No. 488,256. Patented Dec. 20, L892.

Wifnesses lnvenfel' lJNiTnn STATES PATENT Trice.

NATHAN P. STEVENS, OF CONCORD, NEW HAMPSHIRE.

PROCESS OF UNlTlNG BROKEN PIECES OF ARC-LIGHT CARBONS.

SPECIFICATION forming part of Letters Patent No. 488,256, dated December 20, 1892.

Application filed July 1, 1892. Serial No. 438,719. (No model.)

To all whom it may concern.-

Be it known that I, NATHAN P. STEVENS, a citizen of the United States, residing at Concord, in the county of Merrimac and State of New Hampshire, have invented a certain new and useful Improved Process for Uniting Broken Pieces of Arc-Light Oarbons; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates especially to the fragments of arc-light carbons-the pieces which are removed from the lamps each day by the trimmers and replaced by new carbons. Heretofore these pieces of carbon which remain unburned in the lamps after the electric current has been cut off for the night have been a total loss to the light company, as the pieces are much too short to burn a second night; and the object of this invention is to devise the most practical method whereby these waste pieces of carbon may be utilized. The various experiments which I have made and given a practical test during the past three years have resulted in nothing better than the mixture of certain materials that made a cement which under the most favorable circumstances would stick pieces of carbon together sufficientlystron g to be utilized for the lower part of a lamp only ;-and if used in the upper holder by mistake, the pieces would invariably fall apart and the lamp go out. These results all followed the use of any materialas a cement which hardened by exposure to the air and without the application of artificial heat.

To overcome the foregoing difficulties I found it necessary to use for a cement such materials as would be readily applied in the form of a thin paste and rendered sufficiently hard bybeing baked, and to this end my process consists in uniting two or more pieces of carbon by means of a suitable adhesive material which will become hard and strong when subjected to heat, and in baking the same until the joints are thoroughly hard and dry, as fully set forth in the following specification and claims, and clearly illustrated in the drawings accompanying and forming part of same, of which,-

Figure 1, shows in perspective a section of the bench for the operatives, one car, the track, and the baking oven. Fig. 2. is a side elevation of car. Fig. 3. is a plan of same, Fig. 4:. is a perspective view showing a case upon which to place the pieces of carbon when stuck together, for the purpose of holding them in perfect alignment while being baked. Fig. 5. represents the oven partly in cross section and partly in end elevation, and Fig. 6. is a sectional plan of same.

To carry my invention into effect, I face off the ends of the pieces of carbon A, to be united either fiat,one concave and the other convex, or in a form that more nearly resembles a plug socket. Then I apply to the ends to be joined an adhesive substance formed of carbon dust, or pulverized carbon and coal-tar, which is mixed "in about equal quantities and kept while being used at a temperature just below boilin g and a consistency of thin paste. I may then place the carbon thus formed of the pieces A, upon a case or holder B, made of sheet steel in the form of channel iron, in which it may be stood up in an oven to be baked;but this channeled holder B, is notessential except when the pieces to be joined together are trimmed olf flat, or in a form not calculated to hold the pieces in perfect alignment, as shown in Fig. at. The carbons must then be placed in an oven and baked for from one half to three quarters of an hour, and when removed therefrom and cooled they will be equal to newcarbons and thoroughly homogeneous. To join these pieces. together economically it should be done systematically, and in practice I have found some such apparatus as I show in the drawings to be very satisfactory:to wit;a bench 0, having low partitions 0 across its top at convenient distances to accommodate an operative between each, is provided with a slightly elevated track D, upon which cars E, are placed.

The cars are provided with perforations e to let the hot air through their floor, and are open at the top and front side. They may have solid ends e, and slats 6 on the back side connecting their ends as shown. A car is moved along the track in front of the operatives each contributing to its load which may consist of five or six hundred carbons, when the door of the baking oven is opened and the car rolled in, other cars being loaded ter of the car track D. The oven contains an.

inner shell f, which incloses the car load of carbons, and the heat from the gas burners rises at either side of this inner shell f, between its walls and those of the outer .shell F;the latter being perforated at f for the admission of air, and at f for the escape of products of combustion. Vays f are .pro-

vided at each end in which to mount a sliding door F.

Having fully described my invention what I claim is- 1. The process of forming electric arc-light carbons of waste fragments, which consists in facing off or otherwise fitting the adjoining ends and applying thereto a suitable adhesive paste for holding the pieces together, and baking the same until thoroughly homogeneous.

2. The process of converting fragments of electric arc-light carbons into a homogeneous carbon of any desired length which consists in uniting'the pieces by means of a paste composed of pulverized carbon and coal tar, mixed in about equal parts and applied hot, and baking the carbons until hard.

In testimony whereof I affix my signature in presence of two witnesses.

NATHAN 'P. STEVENS."

Witnesses:

J. B. THURsToN, J E. FERNALD. 

